Vibration-damping assembly for a portable cloth-cutting machine



March 31, 1970 J. B. GURY m 3,

VIBRATION-DAMPING ASSEMBLY FOR A PORTABLE CLOTH-CUTTING MACHINE Filed March 2, 1967 INVENTOR FIG. 3 JOHN B. GURY, m 26 M Q ATTOR NEYS United States Eatent O 3,503,160 VIBRATION-DAMPING ASSEMBLY FOR A PORTABLE CLOTH-CUTTING MACHINE John B. Gui-y III, Kirkwood, Mo. J. B. Gury Mfg.

Company, 801 N. Skinker Blvd., St. Louis, Mo. 63130) Filed Mar. 2, 1967, Ser. No. 620,158 Int. Cl. B24b 19/00, 41/00; B26d /08 US. Cl. 51-246 18 Claims ABSTRACT OF THE DISCLOSURE A vibration-damping assembly for a portable clothcutting machine in which a weight is adjustably located along the length of and fixed to an elongate extension on the machine to dampen the vibration of the machine otherwise caused by both the reciprocating movement of the reciprocating means connected to and reciprocating a cloth-cutting knife, and the rotary movement of the rotary means operatively connected to and actuating the reciprocating means, in addition to the movements of other working parts. The elongate extension is tubular and receives a reciprocatively movable threaded rod that carries a knife-sharpening means, the knife-sharpening means being movable reciprocatively along the length of the knife upon actuation of the rotary means.

BACKGROUND OF THE INVENTION This invention relates generally to improvements in a cloth-cutting machine and more particularly to an improved vibration-damping assembly for a portable clothcutting machine.

Portable cloth-cutting machines of the general type presently disclosed are shown in US. Patents Nos. 2,295,- 654; 2,737,763; 2,869,231 and 2,945,332. Heretofore, cloth-cutting machines of this type were limited, as a practical matter, to the length of knife, and therefore, limited to the thickness of cloth that could be cut. Such machines incorporate a reciprocating crosshead that carries the knife, and a rotary means operatively connected to the crosshead for actuation. In addition, a knifesharpening means is mounted for reciprocative movement along the length of the knife during operation. The combined effects of both rotary and reciprocative movements, and the motion of other movable parts, caused an overall vibration in the machine that severely affected the efficient operation and usage of the machine, if the knife length exceeded a limit of approximately eight inches. The operator experienced great difficulty in holding and manipulating such machine because of the extreme vibration of the entire machine, and especially the vibration of the presser foot.

The vibration-damping assembly, constituting the present invention, enables the production and usage of the same type of cloth-cutting machine, but with a considerably longer knife length as for example, substantially fourteen (14) inches, without any objectionable vibration.

SUMMARY OF THE INVENTION The portable cloth-cutting machine has a reciprocating means connected to and reciprocating a knife, and a rotary means operatively connected to and actuating the reciprocating means. A weight is adjustably located along the length of and fixed to an elongate extension on the machine. The selective placement of the Weight dampens the extreme, objectionable vibration of the machine otherwise caused by the combined rotary and reciprocating movements.

The weight includes a tubular sleeve disposed about and receiving the elongate extension, and a resilient cushioning means located operatively between the sleeve and extension. Specifically, the resilient bushing includes a pair of spaced concentric collars, one of which is fixed to the sleeve, and the other of which slidably receives the extension, and a resilient tube retained by and between the collars.

The resilient cushioning means is carried adjacent one end of the elongate tubular sleeve, While the opposite end of the sleeve is free of and radially spaced from the extension, and is capable of radial movement having sufiicient amplitude to compensate for and eliminate or effectively reduce the overall harmonic vibration of the entire machine. It is advantageous to use a resilient pad between the extension and the free end of the tubular sleeve to absorb any force caused by interengagement during vibration of the free end.

A knife-sharpening means associated with the knife is carried by a reciprocatively mounted, threaded rod that is operatively connected to the rotary means for reciprocating the threaded rod inside of the tubular extension and for moving the knife-sharpening means reciprocatively along the knife. The length of the tubular extension is structurally and functionally related to the length of the knife. The longer the knife, the longer the path of travel of the knife-sharpening means, and consequently the longer the tubular extension required to accommodate the longer threaded rod.

The cloth-cutting machine can have a pair of elongate tubular extensions fixed to the machine in adjacent, substantially parallel, side-by-side relation, and arranged in longitudinal, axial alignment with a pair of threaded rods of the knife-sharpening means. A weight is adjust ably located along the length of and fixed to each tubular extension, each weight being individually adjustable to dampen the machine vibration effectively.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational view of the cloth-cutting machine with the knife-sharpening means in a lowered position relative to the knife;

FIG. 2 is a fragmentary front elevational view of the machine, with the knife-sharpening means in a raised position relative to the knife;

FIG. 3 is an enlarged cross-sectional view of the vibration-damping assembly; and

FIG. 4 is a diagrammatic view of the operating mechanism of the machine showing both rotary and reciprocating movements.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now by characters of reference to the drawing, and first to FIG. 1, the cutting machine to which this invention applies may be of any suitable type such as those illustrated and described in US. Patents 2,295,654, 2,737,763, 2,869,231 and 2,945,332. The machine includes a base 10 supporting a standard or pedestal 11 in which an elongate knife 12 is mounted to reciprocate vertically. A handle 13 is usually attached to the standard 11 so that the machine may be manipulated during the cutting operation.

A motor 14 is mounted on and carried by housing 15 from which the pedestal 11 and knife 12 depend. The motor 14 is operatively connected to the knife 12 by a mechanism such as that illustrated and described in US Patent 2,737,763. This connecting mechanism is enclosed within housing 15 and is illustrated diagrammatically in FIG. 4.

As shown in FIG. 4, a shaft 16 drives a fly wheel 17 which has a crank pin 20. The crank pin 20 drives a pitman 21 that drives a crosshead 22 by means of a pin 23. The knife 12 is attached to the lower end of crosshead at 24. The crosshead 22 moves reciprocatively on a pair of spaced, parallel guide pins 25.

Depending from and supported by mechanism within housing 26 attached to the front of housing 15, is a grinder carriage 27 of the knife-sharpening means. The grinder carriage 27 is mounted and guided in its up and down movements in any suitable or desired manner, for example as disclosed in US. Patent 2,737,763.

For example, a pair of screws 30, constituting threaded rods, are driven in opposite directions by a drive connection disclosed in US. Patent 2,737,763, and serve to move the grinder carriage 27 up and down along the knife 12. A driving wheel 32, as shown in FIG. 2, may be provided with a frictional driving contact with the motor 14, the driving wheel 32 operatively interconnecting the motor 14 with the screws to rotate the screws 30 and hence reciprocate the carriage 27, all in a manner disclosed in US. Patent 2,737,763. Again, this mechanism is not shown in any detail because it is not directly involved in this invention.

The knife-sharpening means is fully disclosed in U.S. Patent 2,945,332. Driven by the screws 30 are a pair of drive pulleys 33 and 34. An idler pulley 35 cooperates with the drive pulley 33, While an idler pulley 36 cooperates with the drive pulley 34. An abrasive belt 37 is arranged to run on the pair of pulleys 33 and 35, while a similar, sharpening belt 40 rides on the two pulleys 34 and 36. These belts 37 and 40 are so located as to pass one on each side of the knife 12, the belts 37 and 40 being urged under pressure against the knife 12 while tension is maintained. The knife-sharpening means is carried by the carriage 27 as it moves up and down along the knife 12 in response to the movement of the screws 30.

Mounted on the lower end of a shank 41 vertically slidable within housing 26 and along the carriage 27, is a presser foot 42. As well understood in the art. the presser foot 42 is adjustable to different elevations suited to different layers of material to be cut.

Attached to and extending upwardly from the housing 26 are a pair of elongate, tubular extensions 43, the extensions 43 being disposed in adjacent, substantially parallel, side-by-side relation, and being disposed in longitudinal axial alignment with the pair of screws 30. As will be understood, the screws 30 move upwardly into the elongate tubular extensions 43 as the knife-sharpening means rises, as for example from the position shown in FIG. 1 to the position shown in FIG. 2. In other Words, the pair of screws 30 are located and reciprocatively move in the pair of tubular extensions 43 as the knife-sharpening means moves along the length of the knife 12. Thus, it will be readily understood that the length of the tubular extensions 30 is structurally related to the length of the knife 12 so as to accommodate the travel distance of the knife-sharpening means.

A weight generally indicated by 44 is adjustably located along the length of and fixed to each tubular extension 43. Each weight 44 is individually adjustable along the length of and fixed to its associated tubular extension 43 to dampen the vibration of the machine. The construction and structural arrangement of each weight 44 are identical so that a detailed description of one will suffice for the other.

Each weight 44 includes an elongate tubular sleeve 45 disposed about and receiving an associated tubular extension 43. A resilient cushioning means referred to by 46 is carried adjacent one end of the tubular sleeve 45 and is located operatively between the sleeve 45 and the associated extension 43. This resilient cushioning means 46 includes a bushing having a pair of spaced, concentric collars 47 and 50, one of the collars 47 being fixed to one end of the sleeve 45, while the other collar 50 slidably receives, yet frictionally grips, the extension 43.

A resilient tube 51 is retained by and between collars 47 and 50. The resilient cushioning means 46 supports one end of the tubular sleeve 45 to its associated extension 43.

The remaining length of the tubular sleeve 45 is free of and radially spaced from the extension 43. The free end of the tubular sleeve 45 can vibrate radially from the extension 43 to assist in damping the harmonic vibrations of the entire machine caused by both reciprocative and rotary movements of the operating mechanism. Located between the extension 43 and the free end of the tubular sleeve 45 is a resilient pad 52 that acts to absorb, any force caused by interengagement during vibration of the free end of the tubular sleeve 45.

A fastening means 53, as provided by a set screw, extends through the tubular sleeve 45 and the resilient cushioning means to engage the extension 43 so as to fix the weight 44 in an adjusted position along the length of the extension 43.

It will be understood that the weights 44 are selectively adjustable individually along the length of their associated tubular extensions 43. At some point of location of the weights 44 along the length of the associated extensions 43, the extreme vibration of the entire machine otherwise caused by the harmonic vibrations of the rotary and reciprocating movements of the operating mechanism, will be dampened to eliminate or at least reduce to an acceptable condition the overall vibration of the machine. The operator can then easily guide, manipulate and hold the cloth-cutting machine. The vibration-damping assembly enables portable cloth-cutting machines to be built with longer knife lengths than has been heretofore possible, and thereby enables greater thicknesses of materials to be cut by such machines.

It is thought that the functional advantages of the portable cloth-cutting machine incorporating the vibration-damping assembly have become fully apparent from the foregoing detailed description of parts, but for completeness of disclosure, the operation of the machine and the adjustment of the vibration-damping assembly will be briefly described.

When the motor 14 is energized, the power shaft 16 drives the fly wheel 17 and reciprocates the crosshead 22 through the pitman 21. As the crosshead 22 reciprocates, the knife 12 carried by the crosshead 22 reciprocates correspondingly. In addition, the knife-sharpening means will reciprocate along the length of the knife 12, the screws 30 moving upwardly into and downwardly from the elongate extensions 43. The combined rotary and reciprocating movements of the operating parts sets up harmonic vibrations that cause a severe vibration of the entire machine, and particularly an extreme vibration of the presser foot 42.

To eliminate or substantially reduce the overall machine vibration to an acceptable level, the weights 44 are pressed down over their associated elongate extensions 43. The collar 50 of each resilient cushioning means 46 has a relatively tight, yet slidable, fit with its associated extension 43. Each weight 44 is moved downwardly along the length of the associated extension 43 and is adjustably positioned along the length of such extension 43 until the extreme vibration of the entire machine is reduced to an acceptable level. When the optimum positions of the weights 45 have been found, the weights 44 are fixed securely to their associated extensions by tightening the fastening means 53. i

The resilient pads 52, previously disposed over the elongate extensions 43, are then moved upwardly into the interior of the tubular sleeves 45 adjacent the free ends of such sleeves 45. As mentioned, these resilient pads 52 absorb and isolated any impact forces caused by striking engagement of the sleeves 45 during vibration.

If for any reason the overall harmonic vibration of the machine is changed, such as might occur during wear of parts in the operating mechanism providing both rotary and reciprocating movements, the weights 44 can be readjusted along the length of their associated elongate extensions 43 to reach a new optimum positon that will effectively reduce the extreme vibration of the entire machine.

Although the invention has been described by making detailed reference to a preferred embodiment, such detail is to be understood in an instructive, rather than in any restrictive sense, many variants being possible within the scope of the claims hereunto appended.

I claim as my invention:

1. A vibration damping assembly for a portable clothcutting machine having a reciprocating means connected to and reciprocating a knife, and a rotary means operatively connected to and actuating the reciprocating means, the improvements comprising:

(a) a substantially upright elongate extension on the machine attached to a stationary part thereof, and

(b) a weight adjustably located in embracing relation along the length of and fixed to the elongate extension between the ends thereof to dampen the vibration of the machine otherwise caused by both rotary and reciprocating movements.

2. A vibration-damping assembly for a portable clothcutting machine as defined in claim 1, in which:

(c) the weight includes a tubular sleeve disposed about and receiving the elongate extension, and

(d) a resilient cushioning means located operatively between the sleeve and extension.

3. A vibration-damping assembly for a portable clothcutting machine as defined in claim 1, in which:

(c) the weight includes a tubular sleeve disposed about and receiving the elongate extension, and

(d) a resilient bushing located operatively between the sleeve and extension, the bushing including:

(1) a pair of spaced, concentric collars, one of which is fixed to the sleeve, and the other of which slidably receives the extension, and

(2) a resilient tube retained by and between the collars.

4. A vibration-damping assembly for a portable clothcutting machine as defined in claim 3, in which:

(e) a fastening means secures the weight in adjusted position along the length of the extension.

5. A vibration-damping assembly for a portable clothcutting machine as defined in claim 3, in which:

(e) a fastening means extends through the sleeve and resilient bushing to engage the extension so as to fix the weight selectively in adjusted position along the length of the extension.

6. A vibration-damping assembly for a portable clothcutting machine as defined in claim 1, in which:

(c) the weight includes an elongate, tubular sleeve disposed'about and receiving the elongate extension,

(d) a resilient cushioning means is carried adjacent one end of the tubular sleeve, and is located operatively between the sleeve and extension, and

(e) the opposite end of the tubular sleeve is free of and spaced radially from the extension.

7. A vibration-damping assembly for a portable clothcutting machine as defined in claim 6, in which:

(f) a resilient pad is between the extension and the free end of the tubular sleeve to absorb any force caused by interengagement during vibration of the free end and extension.

8. A vibration-damping assembly for a portable clothcutting machine as defined in claim 6, in which:

(f) the resilient cushioning means includes:

(1) a pair of spaced, concentric collars, one of which is fixed to the sleeve, and the other of which slidably receives the extension, and

collars, and

' (g) a fastening means secures the weight in adjusted position along the length of the extension.

9. A vibration-damping assembly for a portable clothcutting machine having a reciprocating means connected to and reciprocating a knife and a rotary means operatively connected to and actuating the reciprocating means, the machine also having a knife-sharpening means associated with the knife and carried by a reciprocatively mounted, threaded rod, and means operatively connecting the rotary means to the threaded rod for reciprocating the threaded rod and moving the knife-sharpening means reciprocatively along the knife, the improvements comprising:

(a) an elongate extension on the machine attached in a stationary part thereof,

(b) a weight adjustably located along the length of and fixed to the elongate extension to dampen the vibration of the machine otherwise caused by both rotary and reciprocating movements,

(c) the elongate extension being tubular and being fixed on the machine relative to the threaded rod,

(d) the threaded rod being located and reciprocatively moving in the tubular extension as the knifesharpening means moves along the length of the knife, the length of the tubular extension being structurally and functionally related to the length of the knife, and

(e) the weight being adjustably located along the length of and fixed to the elongate tubular extension.

10. A vibration-damping assembly for a portable clothcutting machine as defined in claim 9, in which:

(f) the weight includes an elongate tubular sleeve disposed about and receiving the elongate extension,

(g) a resilient cushioning means is carried adjacent one end of the tubular sleeve, and is located operatively between the sleeve and extension, and

(h) the opposite end of the tubular sleeve beyond the cushioning means is free of and spaced radially from the extension.

11. A vibration-damping assembly for a portable clothcutting machine as defined in claim 10, in Which:

(i) a resilient pad is between the extension and the free end of the tubular sleeve to absorb any force caused by interengagement during vibration of the free end and extension.

12. A vibration-damping assembly for a portable clothcutting machine as defined in claim 10, in which:

(i) the resilient cushioning means includes:

(1) a pair of spaced, concentric collars, one of which is fixed to the sleeve, and the other of which slidably receives the extension, and

(2) a resilient tube retained by and between collars, and

(j) a fastening means secures the weight in adjusted position along the length of the extension.

13. A vibration-damping assembly for a portable clothcutting machine having a reciprocating means connected to and reciprocating a knife and a rotary means operatively connected to and actuating the reciprocating means, the machine also having a knife-sharpening means associated with the knife and carried by a pair of reciprocatively mounted, threaded rods arranged in adjacent, substantially parallel, side-by-side relation, and means operatively connecting the rotary means to the threaded rods for reciprocating the threaded rods and moving the knife-sharpening means reciprocatively along the knife, the improvement comprising:

(a) a pair of elongate, tubular extensions fixed on the machine in adjacent, substantially parallel, sideby-side relation, and in longitudinal, axial alignment with the pair of threaded rods,

(b) the pair of threaded rods being located and reciprocatively moving in the pair of tubular extensions as the knife-sharpening means moves along the length of the knife, the length of the tubular exten- 7 sions being structurally and functionally related to the length of the knife, and

(c) a weight is adjustably located along the length of and fixed to each tubular extension to dampen the vibration of the machine otherwise caused by both rotary and reciprocating movements.

14. A vibration-damping assembly for a portable cloth-cutting machine as defined in claim 13, in which:

(d) each Weight is individually adjustable along the length of and is fixed to its associated tubular extension to dampen the vibration of the machine.

15. A vibration-damping assembly for a portable cloth-cutting machine as defined in claim 13, in which:

(d) each weight includes an elongate tubular sleeve disposed about and receiving its associated elongate extension,

.(e) a resilient cushioning means is carried adjacent one end of each tubular sleeve, and is located operatively between the sleeve and its associated extension, and

(f) the opposite end of each tubular sleeve is free of and spaced radially from its associated extension.

16. A vibration-damping assembly for a portable clothcutting machine as defined in claim 15, in which:

(g) a resilient pad is disposed between each extension and the free end of its associated tubular sleeve to absorb any force caused by interengagement during vibration of the free end and extension.

17. A vibration-damping assembly for a portable clothcutting machine as defined in claim 15, in which:

(g) the resilient cushioning means carried by each sleeve includes:

(1) a pair of spaced, concentric collars, one of which is fixed to the associated sleeve, and the other of which slidably receives the associated extension, and

(2) a resilient tube retained by and in between the collars, and

(h) a fastening means secures each weight in adjusted position along the length of the associated extension.

18. A vibration-damping assembly for a portable clothcutting machine as defined in claim 13, in which:

(d) each weight is individually adjustable along the length of and fixed to its associated tubular extension to dampen the vibration of themachine,

(e) each weight includes an elongate tubular sleeve disposed about and receiving the associated elongate extension,

(f) a resilient cushioning means is carried adjacent one end of each tubular sleeve, the resilient cushioning means includes:

(1) a pair of spaced, concentric collars, one of which is fixed to the associated sleeve and the other of which slidably receives the associated extension, and

(2) a resilient tube retained by and between the collars, the opposite end of each tubular sleeve 7 is free of and spaced radially from the associated extension,

(g) a resilient pad is between each extension and the free end of the associated tubular sleeve to absorb any force caused by interengagement during vibration of the free end, and

(h) a fastening means extends to each sleeve and the associated resilient bushing to engage the associated extension so as to fix the weight selectively in adjusted position along the length of such extension.

References Cited UNITED STATES PATENTS 1,283,895 11/1918 Read 30--2'Z5 2,295,654 9/1942 Gury 51246 FOREIGN PATENTS 11,054 1900 Great Britain.

JAMES L. JONES, 111., Primary Examiner US. Cl. X.R. 

